It seemed as if the R & B visionary was a seriously endangered species, but there's been a decided uptick in intellectual envelope-pushing.

Not all that long ago, it seemed as if the R & B visionary was a seriously endangered species, but there’s been a decided uptick in intellectual envelope-pushing among the genre’s singer-songwriters — some of the most bracing of which has emanated from the women who paired up at Roseland Ballroom on Monday night.

Erykah Badu generated a fair bit of press attention earlier this spring with her “Window Seat” video — a clip that saw her stripped nude and killed at the site of JFK’s assassination. While clearly intended to provoke, the video had more nuance than the thumbnail synopsis might indicate — something that could also be said for the traditional yet demanding performance she put on here.

Dressed in a surprisingly solemn black great coat and top hat, Badu exuded something of a ringmaster’s attitude, conducting her band with flourishes that underscored the vibe. She concentrated heavily on material from her current Universal release “New Amerykah Part Two,” peppering her 90-minute set with relatively faithful versions of fan favorites like “Tyrone” and “On and On,” but allowed those songs to breathe a bit, skipping scatted syllables across measures like stones across a placid pond.

Emphasizing quiet sensuality rather than brassy sexuality, Badu wove a compelling web on laid back versions of songs like “Out My Mind, Just in Time” (on which she was accompanied by little more than tinkling keys and brushed cymbals) and a jazzy, finger-popping “20 Feet Tall.” The sonic and emotional simplicity seemed risky from the onset, but the risk paid off amply.

Equally adventurous was Badu’s decision to tab the mercurial Janelle Monae as an opener. At her best, Monae is capable of blowing most headliners off the stage, and she was at the top of her game here, throwing out lassos of art-funk, techno-pop and space-soul that spun listeners delightfully dizzy. And just when sensory overload was about to take hold, the singer stopped on a dime, dropping into a stark and sincere version of the timeless ballad “Smile.” Before Monae even took the stage, a voice promised “more than just a performance,” and she delivered on that, big time.

Badu and Monae will perform at the Greek Theater in Los Angeles on June 20.